Carlinite

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Carlinite
General and classification
chemical formula Tl 2 p
Mineral class
(and possibly department) 		Sulfides and sulfosalts
System no. to Strunz
and to Dana 		2.BD.25 ( 8th edition : II / B.11)
04/02/13/01
Crystallographic Data
Crystal system trigonal
Crystal class ; symbol trigonal-pyramidal; 3
Space group R 3 (No. 146)Template: room group / 146
Lattice parameters a  = 12.12  Å ; c  = 18.175 Å
Formula units Z  = 27
Physical Properties
Mohs hardness 1.5 - 2
Density (g / cm 3 ) measured: 8.1; calculated: 8.55
Cleavage Perfectly at {0001}, imperfectly prismatic
Break ; Tenacity uneven, irregular
colour dark gray to metallic
Line color dark gray to black
transparency opaque
shine metallic
Crystal optics
Pleochroism Brown-gray to blue-gray
Other properties
Chemical behavior An alkaline reaction in water, oxidizes in air

Carlinite is a very rare mineral belonging to the mineral class of sulfides and sulfosalts. It crystallizes in the trigonal crystal system with the chemical composition Tl 2 S and is therefore chemically thallium (I) sulfide . It forms idiomorphic grains in a weakly developed rhombic form. The mineral has a gray color, metallic sheen and occurs in connection with gold , but also other elements . It has a very low Mohs hardness .

Etymology and history

Carlinite was discovered in 1975 by Arthur S. Radke and Frank W. Dickson in a gold deposit called Carlin in Nevada , USA , from which it was named.

classification

In the old, 8th edition of the Strunz classification of minerals , and in the new 9th edition of the same classification, which is also used by the International Mineralogical Association (IMA), carlinite is classified in the mineral class of sulfides and sulfosalts (more precisely: the Sulfides, selenides, tellurides, arsenides, antimonides, bismuthides, sulfarsenites, sulfantimonites and sulfbismuthites). In both editions it is in the subgroup “Metal sulfides with a metal to sulfur ratio greater than 1: 1”. This group is further subdivided according to the metals involved, so that the mineral can be found according to its composition in the subgroup "with mercury or thallium " (8th edition: "predominantly with copper , mercury or thallium").

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns carlinite to the class of "sulfides and sulfosalts" and there in the department of "sulfides - including selenides and tellurides - with the composition A m B n X p , with ( m + n): p = 2: 1 “a. Here he can be found in the unnamed group 04/02/13 .

Crystal structure

Carlinite crystallizes trigonal in the space group R 3 (space group no. 146) with the lattice parameters a  = 12.12  Å and c  = 18.18 Å as well as 27 formula units per unit cell . Template: room group / 146

properties

As thallium (I) sulfide, carlinite oxidizes in air. It turns darker and loses its shine.

Education and Locations

There are two known locations of Carlinite, both in Lynn District, Nevada, USA. One location is the type locality (location of the first description), the Carlin gold mine, the other is the Deep Post ore deposit .

Carlinite occurs in connection with solid gold, solid arsenic , solid antimony , solid mercury , avicennite ( thallium (III) oxide ), organic carbons and quartz .

See also

literature

Arthur S. Radtke, Frank W. Dickson. Carlinite, TI 2 S, a New Mineral from Nevada. In: American Mineralogist , Vol. 60, 1975, pp. 559–565 ( PDF )

Web links

Individual evidence

  1. ↑ a b c Mineralienatlas: Carlinit
  2. ↑ a b c Carlinite. , In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America , 2001 ( PDF 66.9 kB )
  3. ↑ a b c d Arthur S. Radtke, Frank W. Dickson. Carlinite, TI 2 S, a New Mineral from Nevada. In: American Mineralogist , Vol. 60, 1975, pp. 559–565 ( PDF , English)
  4. ↑ Mindat - Carlinite (English)